1. Field of the Invention
The present invention relates generally to the field of fiber optic scopes used in procedures intended for precise, invasive functions, such as tissue ablation.
2. Information Disclosure Statement
Treatment of cellular tissues usually requires direct contact of the target tissue with a medical instrument, usually by surgical procedures, exposing both the target and intervening tissue to substantial trauma. Often, precise placement of a treatment probe is difficult because of the location of targeted tissues in the body or the proximity of the target tissue to an easily damaged, critical body organ, nerves or other components.
Destruction of cellular tissues in situ has been used in the treatment of many diseases and medical conditions alone or as an adjunct to surgical removal procedures. It is often less traumatic than surgical procedures and may be the only alternative where other procedures are unsafe. Ablative treatment devices have the advantage of using a destructive energy which is rapidly dissipated and reduced to a non-destructive level by conduction and convection forces of circulating fluids and other natural body processes.
Optical fibers (“fibers”) and lasers have been used to destroy malignant, benign and other types of cells and tissues from a wide variety of anatomic sites and organs. This method involves introducing an endoscope to an area adjacent to the tissue to be treated. The fiber is then passed through the endoscope to the treatment zone and radiant energy is applied to the targeted tissue. The fiber can be positioned using a fiber optic viewing system incorporated within the endoscope. Separate components may be included in the system to flush the tissue with fluid.
One example of endoscopic treatment with an optical fiber involves using a side fire optical fiber tip (“side fire”) for use in high power laser applications, as disclosed in U.S. Pub. No. US 2007/0106286 A1, Harschack et al. Side firing directs radiant energy to a treatment area lateral to the endoscope's and fiber's longitudinal axis. One specific application of side fire endoscopic treatment includes treating isolated masses in the prostate gland, for example. The endoscope provides the side fire access to the prostatic mass and radiant energy is directed towards the gland, through walls of the urethra, into the surrounding prostate cells, in an effort to ablate the tissue constricting the urethra.
Endoscopic fiber treatments have complications, however. Once the endoscope and fiber are in position to treat the targeted tissue, the user must be careful and avoid retracting the fiber tip into the endoscope. Excessive retraction allows the fiber to fire inside the endoscope creating several complications. The fiber may blast the endoscope for example, causing expensive or irreparable damage. In addition, reflected radiation can cause self-inflicted damage to the fiber tip, requiring repair or replacement. If damage to the endoscope or fiber tip occurs during a treatment procedure, efficacy is compromised. Damage to either component requires replacement, subjecting the patient to an extended treatment time and increased exposure to anesthesia.
Problems may also occur with excessive fiber extension. Excessive extension may force the fiber tip against body tissue causing it to break. Breakage may once again extend patient treatment time and exposure to anesthesia, if replacement is necessary. In addition, the severed fiber portion may have to be removed from the patient.
The prior art in this field involves the user holding the fiber or a simple handle to manipulate the fiber's position. The user generally tracks the fiber tip's position using a fiber optic viewing system. Beyond viewing the fiber's position, nothing prevents the user from retracting the fiber tip into the endoscope or forcing the fiber tip into tissue.
A precise invasive fiber optic treatment method is disclosed in U.S. Pat. No. 6,200,332 by Del Giglio. The disclosed method involves an optical fiber inserted into a desired treatment area with a needle and fixed hand piece. The user monitors the fiber position visually, typically with the aid of an aiming beam. Positioning of the fiber tip is aided with a notch in the hand piece that remains a fixed distance from the fiber tip. This notch also indicates fiber tip orientation because it remains fixed relative to the direction of the fiber tip. Once in position, the user retracts the needle that delivered the fiber to the treatment site. The retracted needle remains a fixed distance behind the fiber tip. This method requires a dedicated hand piece, introducing needle and a single stroke before moving to another treatment site. It does not address treatments where repeated bursts and movement back and forth along the fiber's axis are required during a single treatment. More significant is the dedicated nature of the device to specific treatments. Further, the device is not adapted for use with an endoscope and cannot itself act as one.
It is an object of the present invention to overcome one or more of the above-described drawbacks and/or disadvantages of the prior art.